<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    .child::after {
        content: "";
        display: inline-block;
        height: 19px;
        width: 33px;
        top: 10px;
        background: url(./new.png) no-repeat;
        animation: updown 0.2s ease-in-out 2.7s infinite alternate;
    }
    /* 上下浮动动画 */
    
    @keyframes updown {
        from {
            transform: translate(0, 0);
        }
        to {
            transform: translate(0, 3px);
        }
    }
</style>

<body>
    <ul class="parent">
        <li class="child">一键海涛</li>
    </ul>
</body>

</html>